1. Field of the Invention
The present invention relates to a selvage-knitting needle mechanism for use in a shuttleless loom for weaving a narrow fabric such as a slide fastener stringer tape.
2. Prior Art
Weaving a narrow fabric or tape on a shuttleless loom requires that the selvage-knitting needle catch a weft loop inserted through a warp shed and projected therefrom, and draw the engaged weft loop through a previous weft loop on the needle, thereby knitting a selvage along an edge of the tape being woven. To perform this task, it is necessary that the selvage-knitting needle reliably engage or catch such projected weft loops without fail.
A variety of selvage-knitting needle mechanisms have been devised to meet such requirements. For example, U.S. Pat. No. 3,102,557, patented Sept. 3, 1963 discloses a selvage-knitting needle that moved upwardly as it moves rearwardly until its hook is above an inserted weft loop, which is then engaged by the hook when the needle starts moving forwardly and downwardly. The upward movement of the needle, however, causes a previous weft loop on a needle shank thereof to be pulled upwardly and enlarged excessively, with the results that the resulting selvage can be irregular in shape, loose, and unsightly. To solve such a disadvantage, a driving mechanism shown in U.S. Pat. No. 3,978,895, patented Sept. 7, 1976, enables the shank of a selvage-knitting needle to be held substantially in a vertical sense whereas the hook moves up and down for reliable weft-loop catching as the needle reciprocates back and forth. The disclosed driving mechanism, however, comprises a complex linkage which is not suitable for a highspeed operation.